Apparatus for heating fluids



Oct. 2, 1945. w. c, SEIFERT 2,385.846

' APRARATUS FOR HEATING FLUIDS 4 Sheets-Sheet 1 Filed April 15, 1941 INYENTOR M'l/z'am C .S

ATTORNEY- 4 Sheets-Sheet 2 mvzmoR: BY William C Jegfirt ATTORNEY V w. c. SEIFERT "APPARATUSFOR HEATING FLUIDS Filed April 15 1941 Oct. 2, 1945.

Oct. 2, 1945. c. SEHIFERT 2,335,846

APPARATUS FOR HEATING FLUIDS Filed April 15, 1941 4,Sheets-Sheet :5

Ot. 2, 1945. v f w. c, SE IFERT v 2,385,346

APPARATUS FOR HEATING FLUIDS Filed April 15', 1941 4 Sheets-Sheet 4 frwenfor William C- Safer-t Patented Oct. 2, 1945 UNITED STATES PATENT OFFICE APPARATUS FOR HEATING FLUIDS William C. Seifert, Narberth, Pa., assignor to Electric Heating Equipment Company, Philadelphia, Pa., a corporation of Delaware Application April 15, 1941, Serial No. 388,642} Claims. (01. 122-332.)

Many ch'emical reactions must, for maximum efliciency, be conducted under closely controlled temperature conditions. Heating of the reacting materials may be effected by circulating a heated fluid in indirect heating relationship to the reacting materials or by conducting a vapor into indirect heating relationship thereto. In order to obtain close control of the reaction temperature the temperature of the heating liquid or the pressure of the heating vapor should be exactly maintained. In practice this presents difiicult ies owing to variations in the heating load as the result of various factors and a lag in the response to such variations of the apparatus in which the heating liquid is heated or the heating vapor is produced. The apparatus of my invention is adapted either to heating a liquid or to heating andvaporizing a liquid. It is adapted, inter alia, to supply a heated liquid to be used to heat indirectly materials undergoing chemical reaction or physical alteration. It is also adapted to heat and vaporize'a liquid to produce a vapor to be similarly used. In either case the response to variations in the applied load is so rapid and complete that the liquid is supplied at a substantially constant temperature or the vapor at a substantially constant temperature and pressure.

The invention will be fully understood from the following description read in conjunction with the drawings in Which- Fig. 1 is a longitudinal vertical section through the apparatus of my invention (a few parts appear in side elevation and not in section) Fig. 2 is a transverse vertical section through the apparatus shown in Fig. 1;

Fig. 3 is a schematic diagram of the apparatus shown in Figs. 1 and 2; and

Fig. 4 is a detail of part of Fig. 3.

Fig. 5 is a detail of part of Fig. 3; and

Fig. 6 is a detail of an alternative form of part of the construction shown in Fig. 3.

Referring to Figs. 1 and 2, the apparatus includes a, receptacle in which fluid is heated or heated and vaporized. In the specific embodiment herein described this receptacle l includes upper drum 2, communicating through duct 3 with intermediate drum 4 which in turn is connected by circulatory tubing 5 with lower drum 6. Tubing 5 (Fig. 2) is bent to define a cylinder 1 into which combustion products are discharged from burner 8 (Fig. 1). Muflle i0 is interposed between the combustion products and the tubing. At the muffle outlet ll these combustion products which have there become reduced in temperature and more uniform in composition are discharged and circulate around the tubing and in contact with the lower part of drum 4 passing off through stack [2. 7 Upper drum 2 carries a number of immersion type heaters l3, l4, l5, l6 and I1. These consist of an electric resistance element carried in a tubular covering from which the resistance element is electrically insulated. Drum 2 is also provided with outlet I 8. Drums 4 and 6 and the connecting tubing 5 are in refractory setting 26. Drum 4 rests'on this setting while drum 2 is supported by I-beams 21 and 28. which rest indirectly on the setting.

If the apparatus is operated to heat fluid, i. e., to heat and deliver unvaporized fluid in liquid phase, the fluid is introduced through inlet 20 and forced by pump 2| driven by motor, 22 through pipe 23 into lower drum 6. Valve 24 may be closed or may be partly open to provide additional circulation between drums 4 and 6 moving downwardly through pipe 25 horizontally through pipe 23 into drum 6, thence upwardly through tubing 5 into drum 4, absorbing heat from burner 8 in passage. From drum 4 it moves through duct 3 into drum 2 in which it absorbs heat from electric heaters l3-I1. The heated liquid leaves the apparatus'through outlet I8. If, conversely, the apparatus is used to heat and vaporize fluid, i. e., to generate and deliver a heating vapor, the condensate is returned to the apparatus through inlet 20. Valve 24 is fully opened and pump 2| is operated to maintain rapid circulation from drum 4 downwardly through pipe 25 horizontally through pipe 23 into drum 6 upwardly through tubing 5 into drum 4 absorbing heat from burner 8 in its passage. From drum 4 it moves through duct 3 into drum 2 in which it absorbs heat from electric heaters I3-l1. The amount of liquid in the system is in this case sufiicient to cover these heaters, but insufiicient to fill drum 2, leaving a vapor space above the liquid while the vapor produced moves out of the apparatus through outlet l8.

The mode of control of the heating or heating and vaporization will be evident from the diagrammatic showing in Figs. 3 and 4. Burner 8 is supplied with oil or other fuel at a constant pressure by pressure reduction valve 30. It receives air through inlet 3|. The amount of fuel and air supplied to the burner and consequently the amount of heat delivered by the burner is regulable by burner control lever 32. This lever is connected through push rod 33 with lever 34 of electric control 35. Lever 34 is pivotally mounted at 36. The upper end of lever 34 carries a strong electromagnet 31 suitably energized. The manner by which the position of lever 34 (and, consequent adjustment of burner control) is determined will be hereinafter described.

With respect to the electric heater I3-l1, one leg of each of these is connected to lead 4|. The other leg of heater I3 is carried to contact l3, of heater M to contact l4, etc. The number of heaters in circuit between leads 4| and 42 is determined by wiping contactor bar 43 carried by lever 44 pivotally mounted at 45. Lever 44 carries strong electromagnet 45'. The manner-by which the position of lever 44 '(and consequent number of .heatersin operation) is determined will be hereinafter described. 7

If the apparatus is used to heat fluid, meter (Fig. 3) is responsive to temperature preferably the temperature of the heated fluid adjacent outlet 18. adapted to this purpose. In this case the meter 5| is assumed to be responsive to slight variations in E. M. F. induced in a thermocouple surrounded by the fluid which is heated and for this purpose the conducting leads NH and I02 are carried from the meter 5| to a thermocouple I03 formed of the dissimilar metals I04 and I95, whicnthermocouple is located in the well 106 located immediately in the path of the liquid moving upwardly through pipe l8. If the apparatus is used to heat and vaporize fluid, the meter 5| may be responsive to temperature but is preferably responsive to the parallel function vapor pressure. In this case the vapor pressure is carried to the instrument from adjacent outlet l8 through pipe 52. A section through outlet l8 and pipe 52 is shown in Fig. 6. Meter 5! is provided with indicating needle 53 which, with increase in temperature or pressure, moves toward the right. The scale 54 includes the predetermined temperature or pressure to be maintained and a range above (right) and below (left). The needle 53 (Fig. 4) is mounted on a wiping contact 55 which in the horizontal movement makes wiping contact with any one of five stationary contacts 61, 62, 63; 64 and 65 or with any one of five stationary contact 1!, l2, 13, M and I5. Wipingcontact 55 is connected to lead 66. Stationary contacts 61-5 inc. are mounted on" an insulating backing and maybe moved horizontally a unit by a worm controlled by hand wheel "61. Stationary contacts ll-5 inc. are mounted on an insulating backing and may similarly be moved horizontally as a unit by a worm controlled by hand wheel 11. Separate control is provided so that one unit may, ifdesired, be set slightly. inadvance of the other, but in general contacts'6l 65' inc. will be exactly above con- ,ta'cts ll-l5 inc. Contacts lit-65' inc. are connected through leads 6t, 62, 63, 64' and 65' to relays "Gl,'-62", 63", 64 and 65", theprimaries of which are in turn connected to lead 65' This is necessary since only currents-of low potential and intensity can be handled by the wiping contact 55. The secondaries oftherelays are connected to lead 68 which is a source of higher potential and intensity and the relays control respectively secondary circuits BI, 82, 83, Blend 85 connected respectively to field magnets BI, 82', 83', 84 and 85'. These are in turn connected'to lead 68'. It is evident from theforegoing that the position of lever 34and consequent burner adjustment is determined by the relative position of indicating needle 53. r In practicethe contacts til-65 inc. are set so'that the central contact 63 will register with needle 53 and wiping contact 55 when the needle is in the-center of the permissive range of temperature or pressure tobe maintained or when the needle isat the exact temperature or pressure to be maintained;- A movement of the needle to the right and therefore to a higher reading results in a shift of the burner to an adjustment of lower heat input and conversely.

'Qontacts 1|,I2, l3, l4 and '15 are connected through leads llf, 12 13, Hi and '15 to relays -|l.'.',-'|2"; 13",' 14" and 15",the primaries of In Fig. 5 I have shown a form' of control It is evident from the foregoing that the position of lever 44 and consequently the number of elect'ric heaters in operation is determined by the relative position of needle 53.

' In operation, therefore, when needle 53 moves to the right from the predetermined point as V the result of or increase in pressure or temperature, both burner and electric heater move automatically to a position of lower heat input. Assuming, for example, that the needle moves to the right'and' wiping .contact55 moves to stationary contacts 55 and .15, .an"immediate and substantial reduction'in'heat input results from putting electric heaters i5 and I5 out of operation. The response of the burner is slower and as soon'as this becomes effective the needle will move toward the temperature orpressure 'to be maintained and wiping con'tact55'will move topo-ints 64 and I4. Whenever the heating load returns to normal the needle will return to its original positionand Wiping contact 55 tocontacts :63 and 13. v

Conversely; when needle 53 moves to the left as the 'resultofa decrease in pressure or temperature, both burner and electric heater move automatically toa position of higher heat input. Assuming, for example, that ithe'nee'dle moves to the left and wiping contact 55 moves to stationary contacts 6| and II, an immediateand sub-' stantial increase in heat input results from putting electric heaters l3 and I4 in operation. The response of the burner '8 is slower and as soonas it: becomes effective the wiping contact 55 moves topoints 92 and F2. Whenever the heating load returns to "normal the needle will return'to its original position and wiping contact tocontact's 63 and 13. V t

, In general the proportionality between electric heat input and non-ielectric heat input (neglecting lag) is substantiallymaintainedthroughout the entire working. range'an'd preferably 'from -85% of the total heat input is non-electric while from 15-40 is electric. 'Ifjhowever, the variations in load "a'rerelatively small, the'proportion of electric tonon-electric heat inputmay 7 also be reduced, itbeing only necessary that the electric heating elements havej a capacity sufficient to enable them to respond immediately to variations inthe heating load, thereby neutralizing the inevitable lag in 'effectivenessof'the nonelectric heating means. 7 I Examples of liquidsi'that maybe heatedor heated and vaporized in my apparatusare water, oil, diphenyl, diphenyl oxide'andmercury; V

The'foregoing description is by Way of illustration and inotiof limitation, and it is, therefore, my intention that the invention be limited only by the appended claims or their equivalents, in which I haveendeavored' to claim broadly all inherent novelty. r

Iclaimg' 11. Apparatus for continuously heating fluid to a predetermined temperature comprising a receptacle subdivided into an ul pgr and atleast one 'lewer drum connected thereto, means for indirectly heating by combustion fluid in said lower responsive to temperature of fluid in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

2. Apparatus for continuously heating fluid to a predetermined temperature comprising a re ceptacle subdivided into an upper and at least one lower drum connected thereto, means for indirectly heating by combustion fluid in said lower drum, means for varying the amount of heat supplied by said heating means, an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistance heater, means responsive to temperature of fluid in said receptacle controlling both said means for varying adapted to vary both said means simultaneously at a rate such that the proportionality between the heat supplied by said first mentioned heater and the heat supplied by said resistance heater is substantially constant throughout the working range.

3. Apparatus for continuously heating fluid to a predetermined temperature comprising a receptacle subdivided into an upper and at least one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said tubing, means for varying the amount of heat supplied by said fuel burner, an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistance heater, means responsive to temperature of fluid in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

4. Apparatus for continuously heating fluid to a predetermined temperature comprising a receptacle subdivided into an upper and at least one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said tubing, means for varying the amount of heat supplied by said fuel burner, an electric resistance heater in said upper drum, means for varying the amount of heatsupplied by said resistance heater, means responsive to temperature of fluid in said receptacle controlling both said means for varying adapted to vary both said means simultaneously one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said tubing, a mufile between said burner and said tubing, means for varying the amount of heat supplied by said burner, an electric resistance heater in said receptacle, means for varying the amount of heat supplied by said resistance heater, and means responsive to temperature of fluid in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

6. Apparatus for continuously heating and vaporizing fluid at a predetermined temperature comprisinga receptacle sub-divided into an upper and at least one lower drum connected thereto, means for indirectly heating by combustion fluid in said lower drum, means for varying the amount of heat supplied by said heating means,

an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistanceheater, means responsive to vapor pressure in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

7. Apparatus for continuously heating and vaporizing fluid at a predetermined temperature comprising a receptacle sub-divided into an upper and at least one lower drum connected thereto, means for indirectly heating by combustion fluid in said lower drum, means for varying the amount of heat supplied by said heating means, an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistance heater, means responsive to vapor pressure in said receptacle controlling both said means for varying adapted to vary both said means simultaneously at a, rate such that the proportionality between the heat supplied by said first mentioned heating means and the heat supplied by said resistance heater is substantially constant throughout the working range.

8. Apparatus for continuously heating and vaporizing fluid at a predetermined temperature comprising a, receptacle sub-divided into an upper drum and at least one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said lower drum, means for varying the amount of heat supplied by said fuel burner, an electric resistance heater in said upper drum, means for Varying the amount of heat supplied by said resistance heater, means responsive to vapor pressure in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

9. Apparatus for continuously heating and vaporizing fluid at a predetermined temperature comprising receptacle sub-divided into an upper drum and at least one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said lower drum, means for varying the amount, of heat supplied by said-fuel burner, an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistance heater, means responsive to vapor pressure in said receptacle controlling both said-means for varying adapted to vary both said means simultaneously at a rate such that the proportionality between the heat supplied by said first mentioned heater and the heat supplied by said resistance heater is substantially constant throughout the working range.

10. Apparatus for continuously heating and vaporizing fluid at a predetermined temperature comprising a receptacle sub-divided into an upper drum and at least one lower drum connected thereto, circulatory tubing communicating with said lower drum, a fuel burner in heating relationship to said tubing, a muffle between said burner and said tubing, means for varying the amount of heat supplied by said burner, an electric resistance heater in said upper drum, means for varying the amount of heat supplied by said resistance heater, and means responsive to vapor pressure in said receptacle controlling both said means for varying adapted to vary both said means simultaneously.

WILLIAM C. SEIFERT. 

